Question

The inlet speeds of coal dust and oxygen blown into gasification chamber are _________ than the velocity of flame propagation

(a) Higher

(b) Lesser

(c) Greater than or equal to

(d) Less than or equal to

This question was posed to me in an international level competition.

Question is taken from Natural Products in section Natural Products of Chemical Technology

Answer 1

Right choice is (a) Higher

Easy explanation: The inlet speeds of coal dust and oxygen must be higher than velocity of flame propagation. Then at the base of chamber ash falls into water seal and hot gases escape through top of the chamber.